S Corrente

Demethylation analysis of the FOXP3 locus shows quantitative defects of regulatory T cells in IPEX-like syndrome

Immune dysregulation, Polyendocrinopathy, Enteropathy X-linked (IPEX) syndrome is a unique example of primary immunodeficiency characterized by autoimmune manifestations due to defective regulatory T (Treg) cells, in the presence of FOXP3 mutations. However, autoimmune symptoms phenotypically resembling IPEX often occur in the absence of detectable FOXP3 mutations. The cause of this “IPEX-like” syndrome presently remains unclear. To investigate whether a defect in Treg cells sustains the immunological dysregulation in IPEX-like patients, we measured the amount of peripheral Treg cells within the CD3+ T cells by analysing demethylation of the Treg cell-Specific-Demethylated-Region (TSDR) in the FOXP3 locus and demethylation of the T cell-Specific-Demethylated-Region (TLSDR) in the CD3 locus, highly specific markers for stable Treg cells and overall T cells, respectively. TSDR demethylation analysis, alone or normalized for the total T cells, showed that the amount of peripheral Treg cells in a cohort of IPEX-like patients was significantly reduced, as compared to both healthy subjects and unrelated disease controls. This reduction could not be displayed by flow cytometric analysis, showing highly variable percentages of FOXP3+ and CD25+FOXP3+ T cells. These data provide evidence that a quantitative defect of Treg cells could be considered a common biological hallmark of IPEX-like syndrome. Since Treg cell suppressive function was not impaired, we propose that this reduction per se could sustain autoimmunity.

Induction of anergic allergen-specific suppressor T cells using tolerogenic dendritic cells derived from children with allergies to house dust mites.

BACKGROUND Dendritic cells (DCs) regulate the immune response to allergens in the lung; they induce either effector or regulatory T cells, which promote or suppress, respectively, the development of allergy. IL-10 is a potent immunosuppressive cytokine that induces type 1 regulatory (Tr1) T cells. OBJECTIVE To generate allergen-specific Tr1 cells in vitro from children with allergy. METHODS Monocyte-derived DCs from children with allergy to house dust mites (HDM) were generated by incubating the cells with IL-10 and pulsing them with Der p 2, a major HDM allergen, or by pulsing them with Der p 2 and incubating them with IL-10 during their last 2 days of differentiation. RESULTS Der p 2-specific T-cell proliferation and T(H)2 cytokine production were significantly reduced when T cells from patients with allergy to HDM were activated with autologous Der p 2-pulsed DCs that had been differentiated or incubated with IL-10. T-cell lines generated with Der p 2-pulsed DCs that were differentiated with IL-10 were hyporesponsive to reactivation with Der p 2 and able to suppress Der p 2-specific T(H)2 effector cells. CONCLUSION Dendritic cells differentiated in the presence of IL-10 and pulsed with allergen gave rise to a population of tolerogenic DCs that induced allergen-specific Tr1 cells. This finding represents an important step forward to the prospective clinical application of tolerogenic DCs to modulate allergen-specific T-cell responses.

Temporary henna tattoo is unsafe in atopic children.

Temporary henna tattoos have become increasingly popular as a safe alternative to permanent tattoos among American and European children and teenagers during the summer holidays. Currently, temporary henna tattoos contain not only henna, but also other additives such as para‐phemylenediamine (PPD), which is considered to be the chemical agent that most frequently causes skin reactions associated with the use of commercial black henna.

Dendritic cells modifi cation during sublingual immunotherapy in children with allergic symptoms to house dust mites

BackgroundThe importance of dendritic cells (DCs) in the initiation of the Th2-mediated inflammatory response to allergens is well known and more recently it has been proposed that DCs have a pivotal role in maintaining tolerance to allergens. The aim of this study was to investigate whether the success of sublingual immunotherapy (SLIT) in allergic asthma is mediated by the induction of changes of DCs functions.MethodsTen children with allergic asthma sensitive to house dust mite were studied before and after 12 months of SLIT. Immature DCs were derived from peripheral blood monocytes cultured for 6 days in presence of interleukin (IL)-4 and GM-CSF and stimulated with lipopolysaccharide for the last 24 hours to induce maturation.ResultsAfter 12 months of SLIT, mature DCs derived from SLIT-treated patients showed a statistically significant defect of CD86 up-regulation, an increase of IL-10, and a reduction of IL-12 production.ConclusionSLIT induces changes in DCs functions that might be responsible for an impairment of T cell activation or drive T cells towards a regulatory activity, thus restoring immune tolerance to allergens.

Happy Air®, a Successful School-Based Asthma Educational and Interventional Program for Primary School Children

Background. To investigate whether an active partnership between schools, parents, and pediatricians can improve the management of asthma and quality of life of children with asthma. Methods. A comprehensive asthma program (Happy Air®), based on a strong family–physician–school relationship, was carried out over a period of 3 years in six primary schools (2765 children). This program provides educational intervention to families, school staff, and students, as well as the administration of written questionnaires to identify children with asthma, asthma diagnosis and management, and, last but not least, extracurricular activities to improve respiratory and psychological conditions. Quality of life of children and parents, at the beginning and end of the program, was assessed using PedsQL™ 4.0 (Pediatric Quality of Life Inventory) measurement model. Result. Asthma was diagnosed in 135 children, of which 37 (27%) were diagnosed de novo. In all children, both single item and total clinical asthma scores showed a significant increase (p < .001) at the end of the Happy Air® program. The average scores of both the total PedsQL™ 4.0 and the four Scales were significantly increased (p < .001). Conclusion. Happy Air® is a model for a strategy of education- and school-based intervention for children with asthma and their families. This multi-action program for diagnosis, clinical follow-up, education, self-management, and quality-of-life control aims to minimize the socioeconomic burden of asthma disease.

Identification of a Btk mutation in a dysgammaglobulinemic patient with reduced B cells: XLA diagnosis or not?

The identification of a Btk mutation in a male patient with <2% CD19(+) B cells warrants making the diagnosis of X-linked Agammaglobulinemia (XLA). Herein we report the case of a 31 year-old male with a gradual decline of peripheral B lymphocytes and low IgA and IgM but normal IgG levels. His clinical history revealed recurrent respiratory and skin infections, sclerosing cholangitis and chronic obstructive pancreatitis. Molecular studies revealed a novel aminoacidic substitution in Btk protein (T316A). His mother, maternal aunts and a maternal female cousin were heterozygotes for the same Btk mutation and were variably affected with pulmonary emphysema. This is a puzzling case where the patients clinical history and laboratory findings divorce molecular genetics. Either this case confirms the variable expressivity of XLA disease or the T316A change in Btk SH2 domain is a novel non-pathogenic mutation and another unknown gene alteration is responsible for the disease.

Correlation of Der p 2 T-cell responses with clinical characteristics of children allergic to house dust mite

BACKGROUND An understanding of the mechanisms responsible for the development and maintenance of allergic inflammation and their clinical implications is needed to develop specific and successful treatment for allergy. OBJECTIVES To characterize in vitro T-cell responses to Der p 2, one of the major allergens of house dust mite (HDM), and investigate potential correlations between clinical and laboratory parameters. METHODS Forty-two patients monosensitized to HDM and 10 age-matched, healthy children were studied. Dendritic cells pulsed with Der p 2 were used to stimulate autologous CD14(-) cells. Der p 2-specific T-cell activation markers, proliferation, and cytokine production profiles were examined. RESULTS Der p 2-specific T-cell activation markers, proliferation, and T(H)2 cytokine production were significantly higher in HDM patients compared with healthy controls. Moreover, a significant correlation between proliferation and T(H)2 cytokine production was observed. Within the allergic group, skin reaction to HDM was significantly stronger in patients with a Der p 2-specific T-cell response. Levels of HDM-specific IgE directly correlated with interleukin 5 and interleukin 13 levels and with skin prick test results and, ultimately, with the patients family history of allergy. Furthermore, the presence of atopic march correlated with T-cell proliferation. CONCLUSION We found that, in HDM patients, Der p 2-specific T(H)2 responses, promoted by autologous dendritic cells in vitro, correlate with clinical parameters.

Happy Air®: A School-Based Educational Program to Maximize Detection of Asthma in Children

Objective. To investigate whether an active partnership among school, parents, and pediatricians allows early identification and treatment of asthmatic children. Methods: An asthma educational program (Happy Air®), based on a strong family-physician-school interrelationship, was performed in six primary schools (2,765 children) before administering a screening questionnaire to the parents. Results. A high response rate (96%) demonstrated 2,649 responders available for the asthma screening: 135 children (5%) received a diagnosis of asthma, of which 37 (27%) were recognized de novo. Conclusion. The active participation of school and parents is the determining factor for the success of an asthma screening program.

Severe Toxoplasma gondii infection in a member of a NFKB2-deficient family with T and B cell dysfunction

We report the case of a 9 years old girl (III.1), first referred at the age of 2 years for alopecia totalis, trachonychia and recurrent respiratory infections. Few months later, she was admitted for pneumonia and adrenal insufficiency secondary to ACTH hormone deficiency. The family history identified grandmother (I.2) and mother (II.2) with common variable immunodeficiency (CVID) (Fig. 1A). Her mother (II.2), also affected by ACTH deficiency, had alopecia areata during childhood. The grandmother (I.2) had developed later in life chronic intestinal CMV infection and died at the age of 68. The immune evaluation of the child showed mild decrease of IgG, low IgM and IgA, absence of isohemagglutinins, low specific response against Tetanus, H. influenzae and S. pneumoniae, but normal against measles and rubella. Immunoglobulin replacement therapy (IgRT) led to improvement of recurrent infections. She had persistent lymphocytosis, with normal T, B and NK distribution. Increased naïve T cell frequency with decreased T cell memory subsetswere reported includingmarked reduction of regulatory T cells (Treg), T follicular helper (Tfh) and Th17. Low Treg was confirmed molecularly by measuring demethylation of the Treg-specificdemethylated region (TSDR) of FOXP3. However, Treg suppressive activity in vitro resulted normal. Decreasedmemory B cells were detected (Table 1) with impaired response to TLR9-ligand CpG. Similar perturbations in T and B cells differentiation were detected in her 36 years old mother (II.2) (Table 1, Supplementary Fig. E1, E2). The trend to increased naive versus memory cells becomes more evident with age, as shown by the mothers percentage of naive T cells (Table 1). Unfortunately data on grandmother (I.2) are not available. Despite CMV and EBV persistent viremia the girl had undergone a complete CMVbut incomplete EBV-seroconversion. The endocrinopathy was not associated with autoantibodies (Abs). However, we found high levels of Abs against multiple type I interferons (IFN-αB2, IFN-α2A, and IFN-ω), type III IFNs (IFN-λ1, IFN-λ2), and IL-12 using protein microarrays. Anti-IFN-ω Abs were confirmed in the patients serum but were absent in themothers (II.2) and grandmothers sera (I.2). At the age of 6 years, the child experienced severe bilateral visual impairment. Neurophysiology studies showed retinal and bilateral optical nerve damage. The MRI